Thread traverse



Jan. 20, 1959 A. CLERC 2,369,797

THREAD TRAVERSE Filed May 14. 1956 2 Sheets-Sheet 1 I a I Jan. 20, 1959 A. CLERC 2,869,797

THREAD TRAVERSE Filed May 14, 195 I 2 Sheets-Sheet 2 Inventor 124 A ttorneys iinite atent 2,869,797 THREAD TRAVERSE Andr Clerc, Geneva, Switzerland, assignor to Societe Rhodiaceta, Paris, France, a corporation of France Application May 14, W56, enial No. 584,766 Claims priority, application France June 8, 1955 6 Claims. (Cl. 242-43) This invention relates to a method and an apparatus for winding a thread onto a bobbin provided at either end with a conical cheek.

in order to wind a thread onto a support in such a way that the length along which winding occurs varies in the course of the winding, it is known to use a thread guide which oscillates with constant amplitude about a fixed point and which has a guide slot in which the thread moves automatically as the diameter of the wound package increases. When the thread is guided by that portion of the slot which is situated between the longitudinal axis of the said support and the pivot point of the thread guide, the increase in the diameter of the wound package forces the thread to move towards the said pivot point and the length along which winding occurs consequently decreases. On the other hand, when the thread is guided by that portion of the slot which is situated on the further side of the longitudinal axis of the winding support with respect to the said pivot point, the increase in the diameter of the wound package causes the thread to move away from the said pivot point, and the length along which winding occurs consequently increases.

It has also been proposed to use such a thread guide for winding a thread on a bobbin having conical cheeks. In this case, the pivot point and the amplitude of the move ment, of the thread guide are so chosen that the slope of the wound package of thread obtained coincides as far as possible with the slope of the checks of the bobbin. Experience, however, shows that with the thread guides known at present it is substantially impossible to obtain a wound package which is perfectly cylindrical over the entire length of the bobbin, even by displacing the pivot point and varying the amplitude of the movement of the thread guide. Alternatively, the wound package does not cover all the space between the cheeks and it consequently collapses and cannot be unwound, or again the thread accumulates close to each cheek and forms a bulge, from which the thread is difiicult to detach during unwinding.

The object of the present invention is to provide a method and apparatus by means of which it is possible to obtain a perfectly cylindrical wound package of thread on a bobbin provided at either end with a conical cheek.

According to the present invention there is provided a method of windina a thread onto a bobbin provided at either end with a conical cheek, comprising feeding the thread through a guide slot in a thread guide and onto the said bobbin, the thread guide being adapted to oscillate about a fixed point, imparting an oscillating movement of constant amplitude to the thread guide, imparting a sudden appreciable increase to the angular velocity of the said;

thread guide before the points at which its direction of movement is reversed, and rapidly restoring the angular velocity to its initial value after a change of direction has occurred. The said increased angular velocity may have the same value before and after the said change of direction. Alternatively the said increased angular velocity ay have different values before and after the said change of direction.

The invention also comprises apparatus for carrying out the said method, the said apparatus comprising a thread guide, provided with a guide slot adapted to oscillate about a fixed pivot point, means for imparting an oscillating movement of constant amplitude to the thread guide, and velocity adjusting means for imparting a sudden appreciable increase to the angular velocity of the said thread guide before the points at which its direction of movement is reversed and for rapidly restoring the angular velocity to its initial value after a change of direction has occurred.

Preferably the said apparatus comprises a reciprocable red, a member pivotally mounted on the rod, the thread guide being connected to the said member for oscillation thereby at a point remote from the pivot point of said member; means for urging the said member into a predetermined position with respect to the rod; and abutment means adapted to engage the said member after it has been moved by the rod a predetermined distance in either direction from a central position, whereby further movement of the said member by the rod away from the central position causes pivotal movement of the said member and hence an increased angular velocity of said thread guide.

The abutment means may be a fixed member provided with a pair of spaced abutments, the fixed member having a plane of symmetry containing the fixed pivot point about which the thread guide oscillates. Alternatively the abutment means may be mounted for reciprocating movement, means being provided for reciprocating the abutment means at a lower linear speed than the said reciprocable rod and out of phase with respect thereto.

The invention is illustrated, purely by way of example, in the accompanying drawings, in which:

Figure l is a diagrammatic view of a first embodiment of apparatus according to the invention and Figure 2. is a diagrammatic view of a second embodiment of the said apparatus.

Referring to Figure 1, a thread guide for the winding of a bobbin B having a conical cheek C at either end comprises a, thread guide lever fl adapted to oscillate about a fixed pivot 2. The lever 1 has at one end a guide slot 3 for the thread (not shown) and, at the other end, a recess 4. Engaged in the said recess 4 is a stud 5 mounted on a diamond-shaped member 6 which is adapted to pivot about a pin 7 secured to a control rod 8. A uniform reciprocating movement is imparted to the control 8 by means not shown. The stud 5 is mounted on the member.

6 at or adjacent to one end of the longer axis of the said member while a fixed pin 9 is mounted on the member 6 at or adjacent to the other end of the said longer axis. Rotatably mounted on the pin 9 is a roller 10. Two re turn springs 11, 12 interconnect opposite sides of the memher 6 with the control rod 8, the said springs being secured to the member 6 adjacent opposite ends of the shorter axis of the said member. The said springs tend-to main tain the longer axis of the member 6 in a predetermined fixed position in relation to the axis of the control rod 8 and to return it to this position when it has been removed therefrom. A fixed member 13, whose plane of symmetry contains the pivot 2, is disposed on the side of the control rod 8 remote from the lever 1. The member 13, which is provided with abutments 14, 15 is so disposed that when the control rod 8 is reciprocated, the roller 10 mounted on the member 6 (which is driven by movements of the rod 3) alternately encounters the abutments l4 and 15.

To illustrate the operation of the apparatus described above, it will be assumed that the means for imparting a reciprocating movement to the control rod 8 is started while the lever l is in the position illustrated in Figure l and that the said movement is first directed from right to left (the thread guide thus turning in the clockwise direction). The control rod 8 will thus drive the member 6 which will move the lever 1 through the engagement of thestud, 5 in the recess 4. When the roller 10 contacts-the abutment 14, the member 6 pivots about the pin 7. The

speed of movement of the stud 5 is thus greatly increased by the action of the member 6 acting as a. lever pivoting 3 about 9, despite the fact that the speed of the control rod 8 has remained constant. Consequently, the angular velocity of the movement imparted to the lever 1 is suddenly appreciably increased.

When the direction of the movement of the control rod 8 is reversed and the rod is moving from left to right, the return springs 11 and 12 turn the member 6 about the pin 7 until the roller is out of contact with the abutment 14. At this instant, the angular velocity of the movement imparted to the lever 1 is suddenly reduced to the value which it had before the roller 10 came into contact with the abutment 14. When the roller 10 driven by the control rod 8 comes into contact with the abutment 15, the angular velocity of the movement imparted to the lever 1 undergoes a further sudden increase. After the reversal of the direction of movement, this velocity remains at the same increased value as long as the roller 10 is in contact with the abutment 15, and it is suddenly reduced when the roller ceases to bear against the abutment 15.

The sudden increase in velocity imparted to thelever 1 can readily be given a desired value by suitably choosing the respective distances of the stud 5 from the pin 7 and of the pin 9 from the pin 7.

It will thus be appreciated that, in the embodiment illustrated in Figure l, the angular velocity of the thread guide lever is suddenly appreciably increased slightly before the points at which the direction of its movement changes, and is suddenly restored to its initial value shortly after the change of direction has taken place, the value of this increased velocity being the same before and after the said change of direction.

In Figure 2, which illustrates a second embodiment, the apparatus is the same as in Figure 1 so far as the elements 1 to are concerned except that the member 13, instead of being fixed, is adapted to slide on two slideways 16 and 17 parallel to the control rod 8. A rotatably mounted shaft 18 is given a uniform rotational movement by means not shown and supports a helically grooved cam 19 which imparts a uniform reciprocating movement to the control rod 8 through a roller 20, the latter being rotatably mounted on a pin 21 fixed to the control rod 8.

The cam 19 also drives a second roller 22 offset in relation to the roller 20, the roller 22 being rotatably mounted on a pin 23 carried by a rod 24 slidably engaged by guides 25, 26. Mounted on the rod 24 is a stud 27 adapted to slide in one of the forks of a double fork member 28 pivotally mounted on a fixed pin 29. The other fork of the member 28 engages a stud mounted on the member 13. The distance of the stud 27 from the pivot pin 29 is greater than the distance of the stud 30 from the said pin 29, and the member 13 is thus given a reciproeating movement parallel to that of the rod 8 but of smaller amplitude. By appropriate choice of the dimensions of the said members and the positions of the rollers 20 and 22, the movement of the member 13 is caused to take place at a lower linear speed than that of the control rod 8 and it is out of phase in point of time with respect to the movement of the control rod 8.

When this phase displacement is a lag, as in the construction illustrated in Figure 2, the movement imparted to the lever 1 has a higher angular velocity immediately after the change of direction of this movement than immediately before the said change of direction.

The opposite result would of course be obtained if the movement of the member 13 were leading with respect to that of the rod 8.

It will thus be appreciated that, in the embodiment illustrated in Figure 2, the angular velocity of the thread guide lever issuddenlyappreciably increased shortly before the points at which the direction of its movement changes and is then's'uddenl estored t'olthe initial value shortly after the change of direction has taken place, but this increased velocity has different values before and after the said change of direction. w

I claim:

1. Apparatus for winding a thread onto a bobbin having a conical cheek at either end thereof comprising a thread guide adapted to oscillate about a fixed pivot point, an elongated guide slot formed in said thread guide, a reciprocable rod; a member pivotally mounted on the rod, the thread guide being connected to the said member for oscillation thereby at a point remote from the pivot point of said member; means for urging the said member into a predetermined position with respect to the rod; and abutment means adapted to engage the said member after it has been moved by the rod a predetermined distance in either direction from a central position; whereby further movement of the said member by the rod away from the central position causes pivotal movement of the said member and hence an increased angular velocity of said thread guide.

2. Apparatus for winding a thread onto a bobbin having a conical cheek at either end thereof comprising a thread guide adapted to oscillate about a fixed pivot point, an elongated guide slot formed in said thread guide; a reciprocable rod; a member pivotally mounted on the rod, the thread guide being connected to the said member for oscillation thereby at a point remote from the pivot point of said member; means for urging the said member into a predetermined position with respect to the rod; fixed abutment means; and a pair of spaced abutments on said abutment means, each said abutment being adapted to engage the said member after it has been moved by the rod a predetermined distance in either direction from a central position; the fixed abutment means having a plane of symmetry containing the fixed pivot point about which the thread guide oscillates; whereby further movement of the said member by the rod away from the central position causes pivotal movement of the said member and hence an increased angular velocity of said thread guide.

3. Apparatus for winding a thread onto a bobbin having a conical cheek at either end thereof comprising a thread guide adapted to oscillate about a fixed pivot point, an elongated guide slot formed in said thread guide; a reciprocable rod; 21 member pivotally mounted on the rod, the thread guide being connected to the said member for oscillation thereby at a point remote from the pivot point of said member; means for urging the said member into a predetermined position with respect to the rod; reciprocable abutment means adapted to engage the said member after it has been moved by the rod a predetermined distance in either direction from a central position; and means for reciprocating the abutment means at a lower linear speed than the said reciprocable rod and out of phase with respect thereto.

4. Apparatus as claimed in claim 3 in which the said reciprocable rod and the abutment means are connected to a common rotatably mounted cam for reciprocation thereby.

5. Apparatus as claimed in claim 4 in which the cam is helically grooved, the reciprocable rod and the abutment means being connected to members engaged in said groove and offset with respect to each other.

6. Apparatus as claimed in claim 5 comprising a member pivotally connected at its opposite ends to the abutment means and to means reciprocated by the cam, the said member being pivoted at a point nearer to the abutment means than to the means reciprocated by the cam.

References Cited in the file of this patent UNITED STATES PATENTS 2,200,388 Finlayson May 14, 1940 2,345,601 Hickes Apr. 4, 1944 1,957,979 Richter May 8, 1934 FOREIGN PATENTS 2,388,557 Little Nov. 6, 1945 212,984 Germany Sept. 4, 1909 

